1. Field of the Invention
This invention relates generally to surge protection devices for protecting telephone/data communications related equipment from power and transient surges. More particularly, it relates to an improved surge protector assembly for protecting telecommunications equipment from power and transient surges occurring on the tip and/or ring conductors of transmission lines connected thereto. Specifically, the surge protector assembly of the instant invention includes a two-piece interfitting housing module of a unique construction and a miniature printed circuit board for mounting surge protector devices, a protector-operational status indicator circuitry, and a ground-connected status indicator circuitry all disposed within the housing module.
2. Description of the Prior Art
As is generally known to those skilled in the telecommunications industry, modern telecommunication equipment is susceptible to transient surges such as those caused by lightning strikes and other voltage/current surges on the transmission lines. Thus, various arrangements of surge protector circuits are known in the prior art which have been provided for connecting to each pair of incoming telephone lines so as to protect the equipment from transient voltage and/or current surges. Each of the incoming telephone lines includes a “tip” line and a “ring” line.
In particular, there is known in the prior art of a 25-pair circuit protection assembly for protecting telecommunications related equipment having up to 25-pairs of wires from transient voltage and/or current surges which is described and illustrated in U.S. Pat. No. 5,483,409. The '409 patent was issued to R. H. Heidorn et al on Jan. 9, 1996 and assigned to the same assignee as that of the present invention which is hereby incorporated by reference in its entirety. As shown in FIGS. 1 through 7, the 25-pair circuit protection assembly includes a two-piece interfitting housing, a printed circuit board sub-assembly, an exposed side connector device, and a protected side connector device. The printed circuit board is mounted inside of the housing and is adapted to receive any number of circuit protector combinations of over-voltage, over-current and line-status devices therein. Schematic circuit diagrams of the various circuit protector devices are illustrated in FIGS. 7, 10, 11 and 16. While the circuit protector devices in FIGS. 10, 11 and 16 each include an indicator circuit which visually indicates the line status and/or blown fuse condition of the particular wire pair, none of these circuit protector devices includes a ground-connected status indicator circuitry for indicating visually whether the surge protector is properly connected to a ground potential.
The present invention represents an improvement over the above-discussed '409 patent in which none of the circuit protector devices provided a ground-connected status indicator circuitry. Therefore, an installer or user was unable to determine whether surge protector was properly connected to a ground connection or whether the ground connected to the surge protector was good or not. The inventors of the present invention have developed an improved surge protector assembly for protecting telecommunications related equipment from power and transient surges which includes a ground-connected status indicator circuitry for indicating visually whether the surge protector has been connected to a ground potential. The main purpose for the provision of the ground-connected status indicator circuitry is because almost all of the surge protectors are typically required to be connected to a ground potential in some fashion. This is due to the fact when a surge or transient occurs on the incoming telephone or data lines it will be diverted to ground in order to protect the equipment. If there is no good ground connection, then the surge protector will not function properly so that the surge will continue on to the equipment which is to be protected, thereby damaging and/or destroying the same.
In the present invention, the housing module has been designed to be mounted upon and for use in conjunction with an extensively used terminal block in the telephone communication industry, conventionally referred to as a “66-M type terminal connector block” that provides rapid wiring installation for key telephone Systems, PBX systems, cables, and other terminal equipment. Typically, these 66-M type terminal connector blocks are mounted on a standoff bracket and serve as an interface with user-provided equipment. A miniature printed circuit board is disposed inside the housing module and is designed to mount any number of surge protector network combinations of over-voltage and over-current protection, protection-operational status indicator circuitry, and ground-connected status indicator circuitry. The protection-operational status indicator circuitry provides a visual indication of the line status and/or blown fuse condition of a particular wire pair. The ground-connected status indicator circuitry provides a means of checking visually whether the surge protector has been properly connected to a ground potential. The housing module has also been designed to include openings formed in its top portion for receiving a protection-operational status indicator and a ground-connected status indicator. The housing module further includes a push-button switch mounted on its one side which is depressable to check for the ground connection.